In indirect aqueous printing, an aqueous ink is jetted onto an intermediate imaging surface, referred to herein as a transfix surface member. The ink is partially dried on the transfix surface member prior to transfixing the image to a print medium, such as a sheet of paper.
As it is important not to disturb the semi-wet ink, non-contact heating is employed to dry the ink. The non-contact heating may be radiant or convection heating; however, convection heating alone may be impractical due to size, cost, and noise.
Radiant heat, while fast acting and effective, is not color blind. Depending on the ink & blanket colors as well as the radiant source wavelengths, significant differences in image temperature may occur. This problem was realized when two blankets with the same fluoroelastomer top coating were tested for two different color substrates. The colors were shown to have very different semi-wet ink temperatures. Specifically, a blue (more reflective) substrate promoted the black ink to heat up much more than the cyan & magenta. A gray (more absorbing) under layer helped to heat the inks more uniformly but was less efficient since it began to heat the bulk of the blanket unnecessarily.
Therefore, techniques for equalizing ink temperature while maintaining thermal efficiency would be desirable in the art.